Codes and Frequencies
VDIFAMOUNT reports respondents' level of difficulty seeing, even when wearing glasses. See the comparability tab for changes in the universe over time.
The Washington Group on Disability Statistics
In 2019, functioning and disability measures included on the NHIS questionnaire were modified to align with validated, internationally-comparable disability measures developed by the Washington Group on Disability Statistics (WG). For more information about the WG initiative, other WG functioning and disability measures included on the NHIS questionnaire, and guidance for researchers about how to use the WG measures in analyses, please see our user note on the Washington Group Disability Measures.
In 2010, this item was collected for sample adults who completed the Quality of Life (QOL) supplement (administered to approximately a quarter of sample adults). In 2011-2017, this item was collected for sample adults who completed the Adult Functioning and Disability (AFD) supplement (administered to a subset of sample adults). In 2018, this item was included on the sample adult questionnaire, and beginning in 2019 was included on both the sample adult questionnaire and the sample child questionnaire. Changes in survey design (e.g., quarters in which the information was collected) may affect raw frequencies, but do not affect comparability of the variable. As always, data users should use the prescribed IPUMS NHIS weights.
The NHIS questionnaire was substantially redesigned in 2019 to introduce a different data collection structure and new content. For more information on changes in terminology, universes, and data collection methods beginning in 2019, please see the user note.
- 1984: Sample persons age 55+ who are not blind in both eyes.
- 2010: One quarter of sample adults (not included in the family disability supplement).
- 2011: Sample adults age 18+ who were selected to receive the family disability questions (FDB).
- 2012-2017: Sample adults age 18+ who were asked the Family Disability questions (FDB) and were randomly selected to receive the Functioning and Disability (AFD) section.
- 2018: Sample adults age 18+.
- 2019-2021: Sample adults age 18+ and sample children age 2 to 17.
- 1984, 2010-2021
- 1984, 2018-2021 : SAMPWEIGHT
- 2010-2017 : SUPP1WT